Bumblebees secrete a substance from their tarsi wherever they land, which can be detected by conspecifics. These secretions are referred to as scent-marks, which bumblebees are able to use as social cues. Although it has been found that bumblebees can detect and associate scent-marks with rewarding or unrewarding flowers, their ability at discriminating between scent-marks from bumblebees of di...

2,4-Pyridinedicarboxylic acid (PDCA) is a structural analog of 2-oxoglutarate and has been shown to inhibit 2-oxoglutarate-dependent dioxygenases by competing with 2-oxoglutarate, and ethylene production in detached carnation flowers by competing with ascorbate on 1-aminocyclopropane-1-carboxylate (ACC) oxidase action. In the present study, the inhibition of ACC oxidase action by PDCA was confi...

Silene alba, a perennial, dioecious plant, produces flowers that open in the evening and can remain open and receptive to pollination for up to 5 d, though in hot and dry conditions the flowers will wilt during the day only to reopen night after night. In the field, it is visited by two different kinds of pollinators with differential success: moths visit the flowers at night, and their movemen...

Colour signals are a major cue in putative pollination syndromes. There is evidence that the reflectance spectra of many flowers target the distinctive visual discrimination abilities of hymenopteran insects, but far less is known about bird-pollinated flowers. Birds are hypothesized to exert different selective pressures on floral colour compared with hymenopterans because of differences in th...

Our understanding of how floral visitors integrate visual and olfactory cues when seeking food, and how background complexity affects flower detection is limited. Here, we aimed to understand the use of visual and olfactory information for bumblebees (Bombus terrestris terrestris L.) when seeking flowers in a visually complex background. To explore this issue, we first evaluated the effect of f...

Flowering plant density can increase number of visits and fruit set in multi-flowering plants, however this aspect has not been studied on few flower species. We studied the effects of individual floral display and plant density on the fruit production of the epiphytic, moth-pollinated orchid, Ryncholaelia glauca, in an oak forest of Chavarrillo, Veracruz, Mexico. Species is non-autogamous, and...

Sir, A 46‐year‐old woman presented with hyperkeratotic eczema and painful fissuring of the thumb, forefinger and third finger of the right hand (her dominant hand) of several months duration [Figure 1a and b]. Her lesions used to subside with the application of topical corticosteroids, but would reappear on stopping them. Detailed questioning revealed that she was in the habit of plucking certa...

Two non-mutually exclusive hypotheses regarding the benefits of andromonoecy (producing perfect and female-sterile flowers on the same plant) are tested using Solanum carolinense. Results indicate that (1) staminate flowers are cheaper to produce than perfect flowers, even after correcting for their relative position in the inflorescence; (2) the resources saved by producing staminate flowers a...

Flower senescence is a highly controlled developmental event that culminates in the death of the floral organs. Most research on flower senescence has focused on the perianth, since it typically determines the commercial life of the flower. The mechanism by which the perianth dies differs between species: in some flowers, wilting is the primary symptom of senescence whereas in others, the peria...

Bauhinia variegata, "PURPLE ORCHID TREE" Spectacular, deciduous tree w/ light green, 2-lobed leaves & 3-in. purple, orchidlike flowers in late winter/early spring (a few may have white flowers). [11] (H*) Caesalpinia mexicana , "MEXICAN BIRD-OF-PARADISE" Heatloving, small tree or large shrub w/ ferny, blue-green leaves & showy clusters of lemon yellow flowers throughout warm weather; needs good...